This latest announcement brings the number of planets discovered by Kepler to a whopping 4,034, 50 of which have been confirmed as being Earth-sized and located within the habitable zone.

“The Kepler data set is unique, as it is the only one containing a population of these near Earth-analogs – planets with roughly the same size and orbit as Earth,” said Mario Perez, Kepler program scientist in the Astrophysics Division of NASA’s Science Mission Directorate.

NASA NASA / Reuters

“Understanding their frequency in the galaxy will help inform the design of future NASA missions to directly image another Earth.”

This latest batch of planetary discoveries marks the final step in Kepler’s observation of the Cygnus constellation.

Kepler discovers new planets by observing the minuscule drop in brightness that occurs when a planet passes in front of its star.

“This carefully-measured catalog is the foundation for directly answering one of astronomy’s most compelling questions – how many planets like our Earth are in the galaxy?” said Susan Thompson, Kepler research scientist for the SETI Institute in Mountain View, California, and lead author of the catalog study.

What makes the discovery all the more astonishing is that not only is the system just 40 light years away from Earth, but that three of the planets discovered are within what we would call the ‘habitable zone’.

Speaking about the discovery Thomas Zurbuchen, associate administrator of the agency’s Science Mission Directorate in Washington said: “Answering the question ‘are we alone’ is a top science priority and finding so many planets like these for the first time in the habitable zone is a remarkable step forward toward that goal.”